package com.atguigu.myjuc.safe;

import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.CopyOnWriteArraySet;

public class NotSafeDemo {
    public static void main(String[] args) {
        //listNotSafe();
        //setNotSafe();
        mapNotSafe();

    }

    public static void mapNotSafe() {
        Map<String, String> map = new ConcurrentHashMap<>();//Collections.synchronizedMap(new HashMap<>()); //new HashMap<>();
        for (int i = 1; i <= 100; i++) {
            new Thread(() -> {
                map.put(Thread.currentThread().getName(), UUID.randomUUID().toString().substring(0, 6));
                System.out.println("map = " + map);
            }, String.valueOf(i)).start();
        }
    }
    public static void listNotSafe(){
        // 读写分离，写时复制
        List<String> list = new CopyOnWriteArrayList<>(); //Collections.synchronizedList(new ArrayList<>()); //new Vector<>(); //ArrayList<>();
        for (int i = 1; i <= 100; i++) {
            new Thread(()->{
            list.add(UUID.randomUUID().toString().substring(0,6));
                System.out.println("list = " + list);
            },String.valueOf(i)).start();
        }
    }
    public static void setNotSafe(){
        Set<String> set = new CopyOnWriteArraySet<>();//Collections.synchronizedSet(new HashSet<>());//HashSet<>();
        for (int i = 1; i <= 100; i++) {
            new Thread(()->{
                set.add(UUID.randomUUID().toString().substring(0,6));
                System.out.println("set = " + set);
            },String.valueOf(i)).start();
        }
    }
}
